Advancement and Tribulations in Ocular Drug Delivery

Abstract

Development of new drug candidates and novel delivery techniques for treatment of ocular diseases has recently accelerated. The field of ocular drug delivery is one of the most interesting and challenging endeavors facing the pharmaceutical scientist for past 10-20 years. In ophthalmic formulation to the eye like solutions, suspensions, and ointments are available in the market shows drawbacks such as increased precorneal elimination, blurred vision and high variability in efficiency. The major setback associated with the conventional dosage forms is the bioavailability of drug. In the last three decades to improve the bioavailability by common to adding viscosity-enhancing agents or mucoadhesive polymers into dosage formulations. To prevail over to conventional dosage formulations there were non-conventional technologies such as lipososme, niosome, microspheres, nanoparticle, implant, gene therapy and ocular inserts could be developed in pharmaceutical market. In this article, we have summarized the different types of commonly used ophthalmic formulations and compared the conventional formulations with the advanced formulation in many respects like their applicability, acceptance, characteristics and utility. „Ocular drug delivery is one of the most interesting and challenging endeavours facing the pharmaceutical scientist...The anatomy, physiology and biochemistry of the eye render this organ exquisitely impervious to foreign substances...The challenge to the formulator is to outwit the protective barriers of the eye without causing permanent tissue damage...The ancient ophthalmic solutions, suspensions and ointment dosage forms are clearly no longer sufficient to combat some present virulent diseases...‰